192.168.1.1 question?

Aside of the "illegal" IP configuration, let's try this concept:

1) If the desktop is wired to the switch, and got a DHCP packet from the router, the switch has learned a routing path via their respective MAC addresses. Hence, going to 1.1, the switch "thinks" the packet must go to the router, since that was the last IP your desktop talked to...

2) Wireless (laptop), if it connects that way, would access the router first, and not have a path known to the switch yet. If the router admin somehow at .1.1 is "routed" to only if there is no other path, then it might get trigggered, but I suspect the switch has somehow notified the router that it is at .1.1, and probably has a better "path cost" to get any packets first.

In other words, if one computer goes thru the switch to the router, a known path via MAC addresses is established. Access from the router's wireless to the switch would be by IP only, since the laptop would be an unknown at first (if accessing over wireless). Once a path is established from laptop to switch, the MAC addresses are stored, and the path may be changed at that point.

Now, if both laptop and desktop are wired to the switch direct, my theory goes out the window... It could be some difference in network adapters, IPV6, or something with network discovery on one of the adapters

Keep the router on DHCP as 192.168.1.1. Make the switch have a static IP of 192.168.1.2. If the router's IP address is 192.168.1.1, it will not assign any device with that same IP address through DHCP. Meaning, the switch must have a default static IP of 192.168.1.1.

As far as a laptop connecting to a different page than a desktop, it must really be just a wireless device connecting to a different page an a wired device. If that's the case, your wireless access point may be interfering. Unplug everything but the router, switch, and one wired computer, then ensure all the IP addresses are correct, then connect everything else.

Each device in the network needs to have its own IP address which is why this is happening. I don't know what your topology looks like, so I can only speculate, but I suspect your devices are connecting to which ever device is first in the arp table at the time.

I'm not sure what you mean by setting the switch to "DHCP Mode", does that mean its getting it's IP address from the DHCP server or that it is the DHCP server?

If "DHCP Mode" means its getting its IP address from your DHCP server, don't. Network devices should have statically assigned addresses programmed at the device which prevents issues like this. Also your device is always at the same IP address. Unplug the router, set the IP information for the switch and plug the router back in. Change the DHCP server settings to exclude your switch's IP address from the dynamic pool so it won't get handed out to a client.

If "DHCP Mode" means your switch is also the DHCP server, then your server isn't setup right. Set the default-gateway or routers option to 192.168.1.1. I'm not familiar with the switch, but any worthwhile DHCP server should exclude this IP from the pool. Might check to be sure. You still want to statically set the IP on switch for management.

This is as much help as I can give with the information given.

Two different devises on the network CANNOT have the same IP address. if you are using the routers DHCP then it will change the IP of the switch. Map the network and get the IP for the switch in get in it that way. Or change to Static IP for internal networking and manually assign IPs

please set static ip addresses for all of your devices. It will make your life so much easier